# Finding the Whole Given Part + Ratio

## Finding the Whole Given Part + Ratio

In this ratio problem, we’re asked to find the total population of a county given the population of one town and the ratio of that town’s population to the rest of the county. **The key to this, like most other ratio problems, is going to be to figure out how many people each one in this ratio represents.**

Because we’re given the population of a town, what we’re going to do is we’re going to divide the population by the number and the ratio that represents the population of the town. **That will tell us how many people each one in the ratio represents.**

Once we have that number, we’ll add these two ratio numbers together and then multiply that number by the number of people that each one represents. Let’s do that. We have 612 people in the town. We’re going to divide it by 17. 17 goes into 61 three times. 3 times 17 is 51.

That leaves us with 10. We’ll add on this 2 here. 17 goes into 102 six times. 6 times 17 is, conveniently, 102. Each number in the ratio represents 36 people. Now to figure out how many people live in the county, we’re going to add these two ratio numbers together, and then multiply that number by 36. We have 17 plus 33.

**This is equal to 50.** Now we have to multiply 50 by 36. What we get now is 5 times 6 is 30. We have a 0, carry a 3. 5 times 3 is 15, plus 3 is 18. We have 1,800 people. In Briscoe County, there are 1,800 residents.